Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo